Vinyl alcohol copolymers containing allylamine functionality

ABSTRACT

A modified poly(vinyl alcohol) copolymer is provided containing copolymerized units of allylamine and/or diallylamine by copolymerizing a vinyl ester, such as vinyl acetate, and an N-allylamide and/or N,N-diallylamide, such as N-allylformamide and/or N,N-diallylformamide and hydrolyzing first the ester groups to hydroxy groups and then the amide groups to amine groups. The second hydrolysis is carried out on solvent-swollen particulate polymer slurried in an acidic or basic medium. The modified polymer can contain small amounts of unhydrolyzed ester and amide groups in addition to the hydroxy and amine functionality which characterizes the copolymer.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of application Ser. No.181,873 now abandoned and Ser. No. 181,887, both filed Apr. 15, 1988.

FIELD OF THE INVENTION

This invention relates to copolymers of vinyl alcohol containingallylamine functionality. In another aspect it relates to a method ofmaking such copolymers using a two-step hydrolysis.

BACKGROUND OF THE INVENTION

Amine-containing polymers are highly useful materials and represent avery cost effective way of incorporating cationic charge into polymersfor uses such as cationic electrocoating, water treatment and enhancedoil recovery. Primary and, to a lesser extent, secondary amines offerthe highest general reactivity spectrum of any group compatible withwater. They will react with anhydrides, epoxides, isocyanates, esters,aziridines, aldehydes, ketones, Michael acceptors, aminoplasts and otheralkylating agents to form covalent linkages. They react with acids andmetal ions to form ionic linkages. Simple derivatives, e.g., Schiffbases, strongly and selectively complex many metal ions. This highreactivity enables many uses in areas such as coatings, adhesives,binders, structural polymers, viscosity control agents, ion exchangeresins, and polymer boundary agents for bio-medical applications.

Because of their high electron donating ability when unprotonated andcationic charge when protonated, amine functional polymers offersuperior adhesion to many types of substrates compared to other polymerswhich are typically neutral or anionic. The ability to change thereactivity and properties of primary or secondary amines by a simple pHchange (addition of acid or base) offers numerous valuable options forviscosity control, emulsion stability control, polymer solubilitymodification (especially in water), or for formulating shelf-stable butreactive crosslinking or substrate reactive systems.

Synthesis of amine functional addition polymers in general is difficultfor two reasons. The simplest amine functional monomer, vinyl amine, isthermodynamically and kinetically unstable relative to the isomericSchiff base and condensation products of the base, ethylidene imine.Also, more stable allyl- and diallyl/amine monomers are expensive andtypically show severe chain transfer during radical polymerization,especially involving allyl protons on carbon atoms alpha to thenitrogen. The allylamines are known to produce mainly low molecularweight polymers and copolymers, even using large amounts of free radicalinitiators.

For many purposes it is desirable to prepare water soluble polymerswhich contain relatively low levels of amine functionality, either toreduce costs by diluting the expensive amine component or forapplications in which a lower level of cationic or reactive amine givessuperior performance. A particularly attractive polymer for certainapplications would be a vinyl alcohol copolymer with a low butcontrollable level of amine functionality.

Preparation of amine functional polyvinyl alcohol (PVOH) has beenpreviously attempted by hydrolyzing copolymers of vinyl acetate andeither N-vinyl-O-t-butyl carbamate or N-vinylacetamide. The carbamatemonomer is prepared by a long and costly synthesis and is reported tohydrolyze to a highly toxic aziridine in the presence of water. In bothcases the poly(vinyl acetate) component was hydrolyzed with methanolicor aqueous base. In the carbamate case, treatment of an aqueous solutionof the poly(vinyl alcohol)-co-poly(N-vinyl-O-t-butyl carbamate) withacid gave the poly(vinyl alcohol)-co-poly(vinylamine) acid salt.Hydrolysis of the poly(N-vinylacetamide) is known to require strong acidat high temperatures. Both approaches produce a relatively diluteaqueous solution of the polymer which is expensive to store or ship orrequires expensive additional steps to isolate the polymer from thesolution. The aqueous solution also contains substantial amounts offrequently undesirable salts or acid.

It has been known for over 30 years that copolymers of vinyl alcoholcontaining a small amount of allylamine functionality could be preparedby copolymerization followed by hydrolysis. In U.S. Pat. No. 2,748,103,Priest (1956), reference is made to a hypothetical copolymer of vinylalcohol and allylamine. This reference describes a method of making suchcopolymers containing 0.1 to 5.0% by weight of allylamines with thebalance of the polymer being vinyl alcohol. The preparation isaccomplished by copolymerizing a vinyl ester, for example vinyl acetate,and N-allylurethane followed by hydrolysis in two steps, first toconvert the acetate groups to hydroxide groups, and secondly to convertthe urethane groups to amine groups. The second step is carried outusing 1 to 3% aqueous sodium hydroxide in the solution at 40°-100° C.

U.S. Pat. No. 3,032,539, Schuller, et al., (1962) disclosescopolymerizating diallylamines and copolymerizable monomers containingethylenic unsaturation such as styrene, vinyl acetate, acrylonitrile,acrylamide, methyl acrylates, and the like. The reference suggests 0.1to 40 mole % diallylamine and 60 to 99.9% comonomer. It is stated thatthe procedure used yields linear polymers instead of a crosslinkedpolymer but the reason for this is not fully understood. There is nodisclosure of converting such polymers by hydrolysis to copolymers ofvinyl alcohol.

U.S. Pat. No. 4,393,174, Dawson, et al., (1983) discloses the basehydrolysis of polymers having pendant amide units, for example,N-vinylacetamide. The amide functionalities are converted with thepolymers in solution to amine functionality using a strong aqueous baseat elevated temperature.

U.S. Pat. No. 4,421,602, Brunnmueller, et al, (1983) describespolymerizing N-vinylformamide and hydrolysis of the formamide group inthe presence of acid or base at 20° to 200° C. to form a polymer having10 to 90% pendent amino groups and 90 to 10% pendent formyl groups. Itis stated that such polymers are useful in paper making.

U.S. Pat. No. 4,490,557, Dawson, et al., (1984) discloses preparingethylidene bisformamide, which is then pyrolyzed to N-vinylformamidewhich is then polymerized and the polymer is acid hydrolyzed topoly(vinylamines).

W. M. Brouwer, et al.; J. Polym. Sci. Polym. Chem. Ed., Vol. 22, pp.2253-2362 (1984) describes the previously mentioned hydrolysis of acopolymer of poly(N-vinyl-O-t-butyl carbamate-co-vinyl acetate) topoly(vinylamines-co-vinyl alcohol). The author points out that the vinylcarbamate produces on aqueous hydrolysis a toxic product ofethylenimine.

R. W. Stackman, et. al.; Ind. Eng. Chem. Prod. Res. Dev., 24, 242-246(1985) describes copolymerization of N-vinylacetamide (NVA) with vinylacetate (VAc) as well as homopolymerization of the N-vinylacetamide.Hydrolysis of the acetamide polymer produces poly(vinylamine). It isstated that hydrolysis of the copolymer involves only the acetate groupsinitially, and hydrolysis of 20:80 NVA:VAc copolymer with base proceededto 70% completion. Hydrolyzed copolymers are said to have formed clearfilms that were tougher than the homopolymer of N-vinylacetamide or theunhydrolyzed copolymer.

U.S. Pat. No. 4,713,236, Hoover, et al., (1987) describes preparation ofa hair conditioning product containing a polymer with pendent amine oramine salt groups. This polymer can be prepared by hydrolysis ofpoly(N-vinylformamide) or poly(N-vinylacetamide). A copolymer ofN-vinylacetamide with vinyl acetate can be formed which on hydrolysisproduces a copolymer containing pendent hydroxyl and amino groups.Partial hydrolysis is said to be a way of modifying the polymer.

U.S. Pat. No. 4,772,359, Linhart, et al., (1988) describes a papermaking process using as drainage aids and flocculants high molecularweight polymers of N-vinylamides, for example N-vinylformamide,including copolymers such as N-vinylformamide with vinyl acetate. Thesepolymers are, however, not hydrolyzed.

U.S. Pat. No. 4,774,285, Pfohl, et al., (1988) describescopolymerization of N-vinylformamide (95-10%) and ethylenicallyunsaturated monomer (5-90 mole %), such as vinyl acetate or vinylpropionate and hydrolyzing 30 to 100% of the monomer units usinghydrochloric acid or sodium hydroxide solution at 20° to 100° C. WhenNaOH solution is used at 50° C., both the N-vinylformamide and the vinylacetate groups are hydrolyzed to about equal extent. The polymers areuseful in paper making.

SUMMARY OF THE INVENTION

According to our invention a process is provided for synthesizingpoly(vinyl alcohol)-co-poly(allylamine) [PVOH/PAAm]. This processenables the efficient hydrolysis of vinyl ester/N-allyl- orN,N-diallylamide copolymer particles in a two phase system yieldingPVOH/PPAm particles which can be readily isolated by filtration.

According to our process a copolymer of poly(vinyl alcohol) containingcopolymerized units of N-allylamide and/or N,N-diallylamide ishydrolyzed by suspending particles of the copolymer in methanol andconverting the amide-containing copolymer to the amine functionalityunder acidic or basic conditions.

Our invention also provides a copolymer of vinyl alcohol containingamine functionality and having the general structural formula ofrandomly interpolymerized monomer units in the indicated molarproportions: ##STR1## wherein R is H, alkyl containing 1 to 11 tocarbons, phenyl, or trifluoromethyl;

R¹ is H, alkyl containing 1 to 4 carbons, or 2-hydroxyalkyl containing 1to 4 carbons;

each R² is H, methyl or trifluoromethyl;

m, n, x, y, a and b are integers which added together make a sum;

m is 0 to 15 percent of said sum;

n is 50 to 99 percent of said sum;

x plus y are 0 to 30 percent of said sum; and a or b can be zero but thetotal of a and b is 1 to 50 percent of said sum except b is greater thanzero when a is less than 5 percent of said sum.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides an industrially attractive process forsynthesizing a poly(vinyl alcohol) copolymer containing copolymerizedunits of allylamine and/or diallylamine by two-phase hydrolysis ofsolvent-swollen particles of the vinyl alcohol copolymer containingcopolymerized units of N-allylamide or N,N-diallylamide. Theamide-containing copolymer is prepared by copolymerizing vinyl acetatewith either or both of N-allylamide, such as N-allylformamide (NAF) andN,N-diallylamide, such as N,N-diallylformamide (NDF). The polymer isformed as a solution in an alcohol and the amide and acetate containingpolymer is then hydrolyzed to convert the acetate functionality, atleast in part, to hydroxyl groups in a methanolic medium thereby forminga poly(vinyl alcohol) copolymer (PVOH) containing the copolymerizedunits of the N-allylformamide and/or N,N-diallylformamide as aparticulate gel swollen with methanol. This particulate gel is thenhydrolyzed while in a slurry in methanol to form the amine-containingcopolymer of poly(vinyl alcohol). These amine units are copolymerizedallylamine (PAAm) or diallylamine (PDAm).

Acid hydrolysis provides a cationic product while base hydrolysis yieldsa salt free, amine functional vinyl alcohol copolymer. The processprovides efficient hydrolysis of the vinyl alcohol-N-allylformamide (orvinyl alcohol N,N-diallylformamide) copolymer particle in a two-phasesystem yielding PVOH/PAAm (or PVOH/PDAm) particles which can be readilyisolated filtration. Since it is not necessary to dissolve the PVOH/PNAF(or PVOH/PNDF) in order to perform the hydrolysis of the amidefunctionality of the copolymer, it is not necessary to precipitate thehydrolyzed product again.

For purposes of describing the invention, a copolymer of formula I willbe discussed, namely poly(vinyl alcohol)-co-poly(allylamine) andreferred to as PVOH/PAAm. Nevertheless, it is to be understood thatPVOH/PAAm can contain some unhydrolyzed vinyl alcohol units as theacetate ester; i.e., vinyl acetate units. Preferably such unhydrolyzedester units are not over 2 mol over 2 mol percent of the polymer.Contemplated as the functional equivalent of vinyl acetate for thepurposes of this invention are vinyl esters of formic acid, other C₃-C₁₂ alkanoic acids, benzoic acid and trifluoroacetic acid. In addition,PVOH/PAAm can also contain some allylamine or diallylamine units as theunhydrolyzed allylamide, i.e., N-allylformamide units. Preferably suchunhydrolyzed amide units are not over 4 mol percent, for example 0.5 to4 mol percent, of the polymer. Contemplated as the functional equivalentof PG,8 N-allylformamide and N,N-diallylformamide for purposes of thisinvention are allylamides and diallylamides such as N-allylacetamide,N,N-diallylacetamide, N-allyltrifluoroacetamide and those amides inwhich the nitrogen is substituted with a C₁ -C₄ alkyl or 2-hydroxyalkylgroup.

The copolymers of the invention have an average molecular weight (Mw)ranging from about 1,000 to 200,000, preferably 5,000 to 130,000.

The process of the invention is described with reference to thepreferred monomers, vinyl acetate and N-allylformamide orN,N-diallylformamide. The abbreviation "PNAF" is meant to indicate thecopolymerized units of N,N-diallylformamide as well as those ofN-allylformamide. The copolymers can be prepared by a free radicalcontinuous or batch polymerization process. The continuous process givesmore uniform molecular weight distribution and uniformity of comonomerincorporation (i.e., a substantially random homogeneous copolymer),improves the lot-to-lot uniformity and offers the commercialattractiveness of continuous operation. The batch process allowsproduction in simple batch equipment and can be carried to highconversion to avoid monomer stripping.

Suitable free radical initiators for the polymerization reaction includeorganic peroxides such as t-butyl peroxypivalate,di(2-ethyl-hexyl)peroxydicarbonate, t-butyl peroxyneodecanoate and2,2'-azobisiso-butyronitrile. The concentration of the initiator in thepolymerization reaction mixture normally ranges from 0.0001-2 wt %, thepreferred concentration being 0.001-0.5 wt %.

Preferably the polymers are prepared using a train of continuous stirredtank reactors followed by a hydrolysis, or alcoholysis, reaction. Vinylacetate, N-allyl- or N,N-diallylformamide, free radical initiator andmethanol are added continuously to the first reactor. The N-allyl- orN,N-diallylformamide comonomer can be added to subsequent reactors inorder to maintain a homogeneous copolymer.

Unreacted vinyl acetate is removed from the exit stream by contacting itwith methanol vapors in a stripping column yielding an intermediatevinyl acetate random copolymer [PVAc/PNAF] having one of the generalformulas II. ##STR2## wherein m=50-99 mole %, preferably 80 to 97 mole%, and

x=1-50 mole %, preferably 3 to 20 mole %, of the sum of m+x.

Although a six-membered ring is shown in the structural formulasderiving from the diallyl monomer, the five-membered ring isomer##STR3## is the functional equivalent in these polymers.

The alcoholysis of the intermediate PVAc/PNAF copolymer is effected bythe addition of a base catalyst. The resulting solid PVOH/PNAF gelswollen by methanol and methyl acetate is ground to give a granularproduct and rinsed with fresh methanol to remove methyl acetate. ThePVOH/PNAF has the following general formula III. ##STR4## where m is0-15 mole %, preferably 0-2 mole % for subsequent base hydrolysis to thevinylamine copolymer,

n is 50-99 mole %, preferably 80 to 97 mole %, and

x is 1 to 50 mole %, preferably 3 to 20 mole % of the sum m+n+x.

Since the copolymer can also be made with both N-allylamide andN,N-diallylamide, the structural formula can also be written toillustrate randomly copolymerized monomer units in the indicated molarproportions, as follows: ##STR5## wherein R is H, alkyl containing 1 to11 carbons, phenyl, or trifluoromethyl;

R¹ is H, alkyl containing 1 to 4 carbons, or 2-hydroxyalkyl containing 1to 4 carbons,

each R² is H, methyl or trifluoromethyl;

m, n, x and y are each positive integers which added together make asum;

m is 0 to 15 percent of said sum;

n is 50 to 99 percent of said sum; and

x or y can be zero but the total of x+y is 1 to 50 percent of said sum.

A suitable process for preparing the PVAc/PNAF and subsequent hydrolysisto PVOH/PNAF is essentially like the process described in U.S. Pat. No.4,675,360 directed to vinyl alcohol/poly(alkyleneoxy) acrylatecopolymers, the disclosure of which is incorporated herein by reference.

Stripping of unreacted vinyl acetate is most conveniently done forcontinuous processes by countercurrent contacting of the polymer pastesolution with hot solvent. Stripping can be avoided by fully convertingthe monomers as in many batch processes. Hydrolysis without priorremoval or reduction of vinyl monomer by polymerization or otherchemical reaction tends to produce unacceptable levels of acetaldehydeand its condensation products. These in turn produce color and maycrosslink PVOH or PAAm groups, reducing polymer solubility.N-allylformamide or other allyl and diallyl amides are more difficult toremove from the solution polymer, but their higher reactivity than vinylacetate in the polymerization and frequently lower levels ofincorporation minimize the amounts of these monomers present in thefinal product. Also, unlike the vinylamides, the allylamides do notimpart acetaldehyde or its condensation products to the final polymer,even if residual levels of unpolymerized monomer are present.

The copolymers of the invention can also contain other comonomers, suchas for example, (meth)acrylate, crotonate, fumarate or maleate esters,vinyl chloride, ethylene, N-vinylpyrrolidone, acrylamide, vinylsulfonatesalts and styrene in amounts ranging up to about 20 mole %.

The hydrolysis of the PVAc/PNAF can be conducted batch or continuouslywith acid or base catalysis in various solvents. It is most convenientlydone, however, in methanol, optionally with various levels of water, viabase catalyzed transesterification. The reaction gives methyl acetate asa volatile coproduct and PVOH copolymer as a solvent-swollen butinsoluble separate phase. The level of PVAc hydrolysis is adjusted byvarying the base addition level and reaction time, but becomesessentially complete during base initiated PNAF hydrolysis in thesubsequent step.

The transesterification solvent (for example, methanol) level can bevaried over wide ranges which should exceed the amount required byreaction stoichiometry and preferably provide sufficiently low viscosityfor efficient mixing of added catalyst and for heat removal. Desirably,a powdery product is obtained directly in a batch hydrolysis using avessel with efficient stirring by adding large amounts of methanol, forexample a 10-fold excess over PVAc copolymer, but high levels ofmethanol give lower polymer throughput or require larger equipment.Continuous hydrolysis of copolymer with base can be convenientlypracticed at 20-60% polymer solids by mixing the base catalyst with thealcohol solution of the copolymer and extruding the mixture onto amoving belt, much as is done commercially for the preparation of PVOHhomopolymer. The hydrolyzed polymer in the form of a methanol/methylacetate swollen gel is then ground and can be rinsed with fresh methanolto remove catalyst residues and methyl acetate. The resultingmethanol-swollen polymer can then be dried or, preferably, used as is inthe subsequent PNAF hydrolysis step.

The hydrolysis of PVOH/PNAF to PVOH/PAAm (or PVOH/PNDF to PVOH/PDAm) canbe accomplished by base or acid hydrolysis. Base hydrolysis, preferablywith alkali hydroxide (NaOH or KOH) or alkaline earth hydroxide,requires 0.7 to 3 times, preferably 1 to 1.5 times, stoichiometricquantities based on PNAF or PNDF, and is best conducted at elevatedtemperatures (50°-80° C.). Although the base or acid hydrolysis reactioncan be accomplished in aqueous solution, the product must then berecovered by precipitation or solvent evaporation. As a slurry ofmethanol-swollen PVOH/PNAF particles in methanol, the two phase reactionis initially fast, but slows down after partial conversion, probablyreflecting slow reaction with less accessible formamide groups.Conversion after 24 hours is about 85% but can be raised to 93% byadding small amounts of water in amounts up to 20 wt %, preferably 1 to10 wt %, based on methanol. The slurry can comprise 10 to 65 wt %,preferably 20 to 50 wt %, copolymer particles in methanol. Contemplatedas the functional equivalent of methanol as the liquid medium of theslurry are C₂ -C₆ alkyl alcohols and diols and C₄ -C₈ alkyl ethers. Themethanol can also contain methyl acetate from the hydrolysis of the PVAccomponent. The two phase hydrolysis has the advantage that the productscan be separated from the liquid phase, rinsed, and dried to produce asalt-free primary amine functional PVOH in a commercially practicableprocess.

The base hydrolysis reaction is best run on substantially fullyhydrolyzed (≧98 mole %) PVOH copolymer.

Acid hydrolysis gives rapid and complete PNAF or PNDF hydrolysis in thecopolymer when conducted at temperatures ranging from 15° to 80° C.Suitable strong acids would include the halogen acids, nitric acid,trifluoroacetic acid and methane sulfonic acid, with hydrochloric acidbeing preferred. Di-and higher valent acids such as sulfuric acid orphosphoric acid are also suitable. Acid in 0.7 to 3 times, preferably 1to 1.5 times stoichiometry based on PNAF or PNDF is required for thishydrolysis reaction with levels near stoichiometric preferred foravoiding post-neutralization of the excess acid. Although acidhydrolysis in aqueous solution is feasible, the reaction is preferablyperformed as a methanol suspension of PVOH/PNAF or PVOH/PNDF particles.Full hydrolysis of the acetate linkages and prior removal of methylacetate are not required with the two phase acid hydrolysis.

Acid hydrolysis is the preferred route to PVOH/PAAm.HX, i.e., where thecharged ammonium salt product is acceptable or desired.

Thus, N-allylformamide and N,N-diallylformamide are used as amineprecursors which copolymerize efficiently with structurally similarvinyl acetate under essentially industry-standard conditions andhydrolyze efficiently under acid or base treatment in a methanol slurryto generate thermally stable reactive primary amines or ammonium saltgroups along the polymer chain. Protection of the amine, as the readilyhydrolyzed formyl derivative in particular, allows surprisingly mildconditions in the final step.

The base hydrolysis step proceeds via essentially full hydrolysis of thePVAc component of the copolymer. The coproduced methyl acetate isoptionally removed by rinsing the particulate, solvent-swollen polymerwith fresh solvent, and then hydrolysis of the still solvent-swollenPVOH/PNAF or PVOH/PNDF particles is rapidly effected by alcohol solublebase. The use of a two phase system, i.e., use of a solvent in which thePVOH/PNAF and PVOH/PAAm are no longer soluble, allows the unreacted baseand salt products to be removed by decantation, centrifugation, orfiltration, and washing, with the copolymer readily recovered in agranular solid form.

Alternatively, acid catalyzed hydrolysis of the ground, solvent-swollenpolymer depends on protonation of the relatively basic formamidenitrogen to give a good leaving group which can be readily displaced bywater or alcohol to give a formate ester or formic acid as products.Unreacted excess acid, salts and by-product formic acid can be removedby decantation or filtration and washing to give a granular solidproduct.

The invention can be further understood by reference to the followingexamples which are presented for illustration of specific embodimentsonly and should not be construed to limit the invention unduly.

EXAMPLE I Preparation of N-allylformamide

Methyl-t-butyl ether (MTBE) (200 g) and 1.2 moles of ethyl formate werecombined in a 100 mL 3-neck flask equipped with mechanical stirrer,thermometer, water condenser, 100 mL addition funnel and N₂ blanket.N-allylamine (1.0 mole) was weighed into the addition funnel and addedover 30 minutes. The reaction was stirred vigorously for 1.5 hours withno increase in temperature. A magnetic stirrer replaced the mechanicalstirrer and the reaction mix was left over the weekend. MTBE and ethanolwere removed using a rotary evaporator. The reduced solution was vacuumdistilled. Approximately 25 mL of ethanol distilled off first.N-allylformamide (NAF) distilled at 134° C./51 torr, which is inapproximate agreement with the literature: Saegusa, et al., Bulletin ofChemical Society of Japan, Vol. 42, pg. 2610-2614 (1969) reports120°-122° C./48 torr. The 79 g collected gave a yield of 93%. Gaschromatographic analysis showed 99+% purity. Structure was confirmed byNMR.

EXAMPLE II Preparation of N,N-diallylformamide

Ethyl formate (55.6 g, 750 mmole) and 37.5 g (385 mmole) of N,N-diallylamine were combined in a 250 mL 3-neck flask equipped with mechanicalstirrer, Friedrich condenser, and N₂ blanket. The reaction mixture wasstirred at reflux temperature (120° C. oil bath) for 24 hours and thensampled by GC to determine if all the N,N-diallylamine was reacted, RTof 0.4 mm. The product was vacuum distilled using a 1-piece apparatuswith a fractionation column. The first fraction distilled at 30° C./16torr. The second fraction N,N-diallylformamide (NDF), distilled at88°-90° C./10-14 torr. The yield was 95%. Structure was confirmed byNMR.

EXAMPLE III Preparation of poly(vinyl acetate)/6% poly(N,N-diallylformamide) at 45% monomer concentration (PVAc/6% PNDF)

To a 1 L resin kettle equipped with condenser, N₂ -inlet, thermometer,thermowatch, mechanical stirrer, and heating mantle were added vinylacetate (125.5 g), N,N-diallylformamide (11.65 g), methanol (167 g),tartaric acid (0.05 g) and Trigonox (t-butylperoxyneodecanoate, Nauri)(0.11 g). The resulting solution was purged with N₂ for 1 hour, and thenheated to 60° C. While maintaining the reaction temperature at 60° C.,0.66 g Trigonox (in 30 g MeOH, 0.05 g tartaric acid) was added into thereaction mixture over 6 hours. After an additional 18 hours, theresulting polymer solution was cooled to room temperature and wasdirectly usable for the subsequent hydrolysis (VAc conversion=39%).

Hydrolysis of PVAc/6% PNDF to PVOH/6% PNDF

PVAc/6% PNDF polymer paste as prepared above was diluted with methanolto give a 10% solution. Unreacted vinyl acetate monomers in the polymerpaste were then distilled off. The resulting solution was heated to 65°C., and KOH (0.02 eq. on VAc) in 10 g of methanol was then added intothe polymer solution over 1 hour. The polymer precipitated as a whitepowder near the end of catalyst addition. After stirring for one morehour at 65° C., the polymer slurry was cooled and filtered.

Hydrolysis of PVOH/6% PNDF to PVOH/6% PDAm

The wet polymer powder was washed with methanol twice and thentransferred to a 3-neck round bottomed flask equipped with condenser, N₂-inlet, thermometer, thermowatch, mechanical stirrer, and heatingmantle. Methanol (160 g) and aqueous hydrochloric acid (3 eq. on DAF)were added. The resulting polymer suspension was heated to reflux for 12hours. The final polymer was filtered, washed, and dried (yield=71%).

EXAMPLE IV Preparation of poly(vinyl acetate)/6%poly(N,N-diallylformamide) at 65% monomer concentration (PVAc/6% PNDF)

To a 1 L resin kettle equipped with condenser, N₂ -inlet, thermometer,thermowatch, mechanical stirrer, and heating mantle were added vinylacetate (125.5 g), N,N-diallylformamide (11.65 g), methanol (74.4 g),tartaric acid (0.05 g) and Trigonox (0.11 g). The resulting solution waspurged with N₂ for 1 hour, and then heated to 60° C. While maintainingthe reaction temperature at 60° C., 0.66 g Trigonox (in 30 g MeOH, 0.05g tartaric acid) was added into the reation mixture over 6 hours. Afteran additional 18 hours, the resulting polymer solution was cooled toroom temperature and was directly usable for the subsequent hydrolysis(VAc conversion=75%).

Hydrolysis of PVAc/6% PNDF to PVOH/6% PNDF

PVAc/6% PNDF polymer paste as prepared above was diluted with methanolto give a 10% solution. Unreacted vinyl acetate monomers in the polymerpaste were then distilled off. The resulting solution was heated to 65°C., and KOH (0.02 eq. on VAc) in 10 g of methanol was then added intothe polymer solution over 1 hour. The polymer precipitated as a whitepowder near the end of catalyst addition. After stirring for one morehour at 65° C., the polymer slurry was cooled and filtered.

Hydrolysis of PVOH/6% PNDF to PVOH/6% PDAm

The wet polymer powder was washed with methanol twice and thentransferred to a 3-neck round bottomed flask equipped with condenser, N₂-inlet, thermometer, thermowatch, mechanical stirrer, and heatingmantle. Methanol (160 g) and aqueous hydrochloric acid (3 eq. on DAF)were added. The resulting polymer suspension was heated to reflux for 12hours. The final polymer was filtered, washed, and dried (yield=77%).

EXAMPLE V Preparation of poly(vinyl acetate)/12% poly(N,N-diallylformamide) at 65% monomer concentration (PVAc/12% PNDF)

To a 1 L resin kettle equipped with condenser, N₂ -inlet, thermometer,thermowatch, mechanical stirrer, and heating mantle were added vinylacetate (117.3 g), N,N-diallylformamide (23.3 g), methanol (75.7 g),tartaric acid (0.05 g) and Trigonox (0.11 g). The resulting solution waspurged with N₂ for 1 hour, and then heated to 60° C. While maintainingthe reaction temperature at 60° C., 0.66 g Trigonox (in 30 g MeOH, 0.05g tartaric acid) was added into the reaction mixture over 6 hours. Afteran additional 18 hours, the resulting polymer solution was cooled toroom temperature and was directly usable for the subsequent hydrolysis(VAc conversion=59%).

Hydrolysis to PVOH/12% PNDF

PVAc/12% PNDF polymer paste as prepared above was diluted with methanolto give a 10% solution. Unreacted vinyl acetate monomer in the polymerpaste was then distilled off. The resulting solution was heated to 65°C., and KOH (0.02 eq. on VAc) in 10 g of methanol was then added intothe polymer solution over 1 hour. The polymer precipitated as a whitepowder near the end of catalyst addition. After stirring for one morehour at 65° C., the polymer slurry was cooled and filtered.

Hydrolysis to PVOH/12% PDAm

The wet polymer powder was washed with methanol twice and thentransferred to a 3-neck round bottomed flask equipped with condenser, N₂-inlet, thermometer, thermowatch, mechanical stirrer, and heatingmantle. Methanol (160 g) and aqueous hydrochloric acid (3 eq. on DAF)were added. The resulting polymer suspension was heated to reflux for 12hours. The final polymer was filtered, washed, and dried.

EXAMPLE VI Preparation of poly(vinyl acetate)/3%poly(N,N-diallylformamide)

To a 1 L resin kettle equipped with condenser, N₂ -inlet, thermometer,thermowatch, mechanical stirrer, and heating mantle were added vinylacetate (129.3 g), N,N-diallylformamide (5.82 g), methanol (73.2 g),tartaric acid (0.05 g) and Trigonox (0.11 g). The resulting solution waspurged with N₂ for 1 hour, and then heated to 60° C. While maintainingthe reaction temperature at 60° C., 0.66 g Trigonox (in 30 g MeOH, 0.05g tartaric acid) was added into the reaction mixture over 6 hours. Afteran additional 18 hours, the resulting polymer solution was cooled toroom temperature and was directly usable for the subsequent hydrolysis.

Hydrolysis to PVOH/3% PNDF

PVAc/3% PNDF polymer paste as prepared above was diluted with methanolto give a 10% solution. Unreacted vinyl acetate monomer in the polymerpaste was then distilled off. The resulting solution was heated to 65°C., and KOH (0.02 eq. on VAc) in 10 g of methanol was then added intothe polymer solution over 1 hour. The polymer precipitated as a whitepowder near the end of catalyst addition. After stirring for one morehour at 65° C., the polymer slurry was cooled and filtered.

Hydrolysis to PVOH/3% PDAm

The wet polymer powder was washed with methanol twice and thentransferred to a 3-neck round bottomed flask equipped with condenser, N₂-inlet, thermometer, thermowatch, mechanical stirrer, and heatingmantle. Methanol (160 g) and aqueous hydrochloric acid (3 eq. on DAF)were added. The resulting polymer suspension was heated to reflux for 12hours. The final polymer was filtered, washed, and dried (yield=88%).

Molecular weight distributions of the cationic polymers of Example III(PVOH/6% PDAm) and Example VI (PVOH/3% PDAm) are given in Table 1.

                  TABLE 1                                                         ______________________________________                                        Polymer       Mw      Mn       Mw/Mn  I.V.*                                   ______________________________________                                        PVOH/6% PDAm  10,700  4,020    2.7    0.26                                    PVOH/3% PDAm  21,900  2,890    7.6    0.33                                    ______________________________________                                         Absolute values from SEC/DV                                                   Conditions:                                                                   Mobile Phase  0.1% TFA/0.10M sodium nitrate                                   Temperature  35° C.                                                    Columns  CATSEC (Polyvinylamine coated), Synchrom, Inc.                       Standards  Poly(2vinylpyridine)                                               *I.V. is intrinsic viscosity.                                            

EXAMPLE VII Preparation of poly(vinyl acetate)/6% poly(N-allylformamide)

To a 1 L resin kettle equipped with condenser, N₂ -inlet, thermometer,thermowatch, mechanical stirrer, and heating mantle were added vinylacetate (125.5 g), N-allylformamide (11.65 g), methanol (72.3 g),tartaric acid (0.05 g) and Trigonox (0.11 g). The resulting solution waspurged with N₂ for 1 hour, and then heated to 60° C. While maintainingthe reaction temperature at 60° C., 0.66 g Trigonox (in 30 g MeOH, 0.05g tartaric acid) was added into the reaction mixture over 6 hours. Afteran additional 18 hours, the resulting polymer solution was cooled toroom temperature and was directly usable for the subsequent hydrolysis(VAc conversion=37%).

Hydrolysis to PVOH/6% PNAF

PVAc/6% PNAF polymer paste prepared above was diluted with methanol togive a 10% solution. Unreacted vinyl acetate monomer in the polymerpaste was then distilled off. The resulting solution was heated to 65°C., and KOH (0.02 eq. on VAc) in 10 g of methanol was then added intothe polymer solution over 1 hour. The polymer precipitated as a whitepowder near the end of catalyst addition. After stirring for one morehour at 65° C., the polymer slurry was cooled and filtered.

Hydrolysis to PVOH/6% PDAm

The wet polymer powder was washed with methanol twice and thentransferred to a 3-neck round bottomed flask equipped with condenser, N₂-inlet, thermometer, thermowatch, mechanical stirrer, and heatingmantle. Methanol (160 g) and aqueous hydrochloric acid (3 eq. on AF)were added. The resulting polymer suspension was heated to reflux for 12hours. The final polymer was filtered, washed, and dried.

Other aspects and embodiments of our invention will be apparent to thoseskilled in the art from the foregoing disclosure without departing fromthe spirit or scope of the invention.

We claim:
 1. A process for making a poly(vinyl alcohol) copolymercontaining copolymerized units of allylamine or diallylamine or bothwhich comprises suspending in methanol particles of a poly(vinylalcohol) copolymer containing copolymerized units of N-allylamide orN,N-diallylamide or both and hydrolyzing said amide-containing copolymerparticles under acidic or basic conditions to form particles of saidamine-containing copolymer.
 2. The process of claim 1 wherein thehydrolysis is performed using basic conditions to yield salt freeparticles of said amine-containing copolymer.
 3. The process of claim 1wherein the hydrolysis is performed under acidic conditions to yieldparticles of the corresponding acid salt of said amine-containingcopolymer.
 4. The process of claim 1 wherein said poly(vinyl alcohol)amide-containing copolymer can be represented by the followingstructural formula having randomly copolymerized monomer units in theindicated molar proportions: ##STR6## wherein R is H, alkyl containing 1to 11 carbons, phenyl, or trifluoromethyl;R¹ is H, alkyl containing 1 to4 carbons, or 2-hydroxyalkyl containing 1 to 4 carbons, each R² is H,methyl or trifluoromethyl; m, n, x and y are integers which addedtogether make a sum; m is 0 to 15 percent of said sum; n is 50 to 99percent of said sum; and x or y can be zero but the total of x+y is 1 to50 percent of said sum.
 5. The process of claim 4 wherein the hydrolysisis performed under basic conditions and m is 0 to 2 percent of said sum.6. The process of claim 4 wherein x is zero, and R is methyl and R² ishydrogen.
 7. The process of claim 4 wherein y is zero, R is methyl, andR¹ and R² are hydrogen.
 8. A process for making a poly(vinyl alcohol)copolymer containing copolymerized units of allylamine and/ordiallylamine which comprises:(a) copolymerizing vinyl acetate witheither or both of N-allylformamide and N,N-diallylformamide to form apoly(vinyl acetate) copolymer containing copolymerized units ofN-allylformamide or N,N-diallylformamide or both in an alcohol solution,(b) hydrolyzing the acetate functionality of said poly(vinyl acetate)copolymer in a methanolic medium to form a poly(vinyl alcohol) copolymercontaining copolymerized units of N-allylformamide orN,N-diallylformamide or both as a particulate gel swollen with methanol,and (c) hydrolyzing said particulate gel as a slurry in methanol with 0to 20 percent water to form said amine-containing copolymer ofpoly(vinyl alcohol).
 9. The process of claim 8 wherein said alcohol ismethanol, said solution of step (a) is diluted with methanol andunreacted vinyl acetate is distilled therefrom prior to step (b), saidparticulate gel from step (b) is filtered and washed with methanol priorto step (c), and the product of step (c) is separated, washed withmethanol and dried.
 10. The process of claim 8 wherein said hydrolyzingof step (b) is under basic conditions and said hydrolyzing of step (c)is under acidic conditions.
 11. A copolymer of vinyl alcohol containingamine functionality and having the structural formula of randomlyinterpolymerized monomer units in the indicated molar proportions:##STR7## wherein R is H, alkyl containing 1 to 11 carbons, phenyl, ortrifluoromethyl;R¹ is H, alkyl containing 1 to 4 carbons, or2-hydroxyalkyl containing 1 to 4 carbons; each R² is H, methyl ortrifluoromethyl; m, n, x, y, a and b are integers which added togethermake a sum; m is 0 to 15 percent of said sum; n is 50 to 99 percent ofsaid sum; x plus y are 0 to 30 percent of said sum; and a or b can bezero but the total of a and b is 1 to 50 percent of said sum, exceptthat b is greater than zero when a is less than 5 percent of said sum.12. The copolymer of claim 11 wherein R is methyl, R¹ and R² arehydrogen, m is 0 to 2 percent of said sum, n is 80 to 97 percent of saidsum, x plus y are 0 to 4 percent of said sum, and a plus b are 3 to 20percent of said sum.
 13. The copolymer of claim 12 wherein y and b arezero.
 14. The copolymer of claim 12 wherein x and a are zero.
 15. Thecopolymer of claim 13 wherein x is 0.5 to 4 percent of said sum.
 16. Thecopolymer of claim 14 wherein y is 0.5 to 4 percent of said sum.